A surface enhanced Raman scattering unit including a support having a cavity provided with an opening, and a surface enhanced Raman scattering element including an optical functional portion that causes surface enhanced Raman scattering (SERS) and disposed in a cavity is known as a surface enhanced Raman scattering unit of the related art (see, for example, Patent Literatures 1 to 3). In the surface enhanced Raman scattering unit, the optical functional portion easily deteriorates due to oxidation due to moisture, adhesion of foreign matters, physical interference, or the like. In order to prevent the deterioration of the optical functional portion, the opening of the cavity is covered with an easily breakable cover in a device described in Patent Literature 3.